This invention relates to the field of preparing food products in tubular casings and enclosing the products in netting. One method generally used in the industry is to pump food products, such as pasty sausage meat, whole muscle meats, or otherwise, through a product horn. The food products are forced into a tubular casing, which can be a pre-formed tube that is shirred onto the product horn, or a tube formed continuously from flat sheets of film. The tubular casing expands as filled into a coaxial netting. After processing, such as cooking or smoking, the netting will be removed, leaving a dimpled appearance on the food products that is considered pleasing to consumers. The edible casing will prevent the netting from sticking to the food product, so upon removal of the netting a clean appearance of the meat is maintained. (This process is not limited to meat; it can be used for cheeses, for vegetarian sausage, or for anything else for which a dimpled appearance is desired.)
The netting used in this process arrives from the manufacturers in a flattened state and wrapped circumferentially on a disposable cylinder. The netting has to be shirred onto a temporary netting tube. This shirring process, or “rucking”, involves placing the netting coaxially onto the netting tube. The temporary netting tube, having had netting shirred or rucked onto it, is then attached coaxially to the product tube of a stuffer. As the food product is forced through the product horn, the netting is pulled off the netting tube so that the now-filled casing is enclosed in netting. The process is described in, for example, U.S. Pat. No. 7,063,610, the disclosure of which is incorporated by reference.
In this process, the netting is pulled freely so long as the product continues to exert pressure. The user of the apparatus determines by estimation the point at which to seal the sausage by clipping the netting and casing. Accordingly, the sizes of sausages prepared vary according to the accuracy of the operator. Consumers prefer to have consistent sizes of sausages. Additionally, it is easier for the sausage manufacturer to package sausages of a predetermined, consistent size, and the need to weigh individual packages may be obviated if the sausages are of a consistent size.
A need therefore exists for an apparatus that will prepare sausages of a predetermined and consistent length. The present invention, by allowing only a predetermined amount of netting to be derucked from the netting tube, meets this need.